Casting apparatus



Nov. 25, 1952 T. o. zscHoKKE CASTING APPARATUS 2 SHEETS-SHEET l Filed OOb. 20, 1948 INVENTOR @/ffcO/f/f@ /77'7'ORNEy #2re A BY Nov. 25, 1952 T. o. zscHoKKE CASTING APPARATUS 2 SHEETS-SHEET 2 INVENTOR.

Filed Oct. 20, 1948 Patented Nov. 25, 1952 UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 IO. G. 757) 7 Claims.

The invention described herein, if patented, may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to the casting of concrete structures and particularly concrete pipe, and has for its primary object to provide a mechanism capable of casting a monolithic pipe in situ in a continuous manner.

A further object of the invention resides in the provision of a core capable of being everted so as to form, in effect, a continuously moving core around which the pipe may be cast.

Another object of the invention consists in the provision of means for everting the core as the casting operations progress.

Other objects and advantages of the invention will be apparent from the following description when taken in connection with the accompanying drawings, in which:

Figure 1 is a longitudinal sectional view through a ditch or trench showing various parts of the mechanism employed in casting in continuous manner a monolithic type concrete pipe;

Figure 2 is a longitudinal section on an enlarged scale of the evertible tube used in the continuous casting of concrete pipe, parts being broken away;

Figure 3 is a cross-sectional View taken on the line 3-3 of Figure 2;

Figure 4 is a view similar to Figure 1 showing substantially the same elements of the mechanisrn except for a modification of the means used for everting the core;

Figure 5 is a longitudinal sectional View on an enlarged scale of the core and everting mechanism of Figure fi;

Figure 6 is an end view of the core, and

Figure 7 is a sectional View taken on thel line Tl-l of Figure 5.

While the mechanism to be used in the continuous casting in situ of a concrete pipe of monolithic form is a complete and integrated one; it is not deemed to be necessary or desirable to show tand describe a number of the elements which are yof conventional form. Consequently, the drawings show only those parts of the mechanism which are peculiar to the particular` apparatus.

Referring first to Figures l, 2 and 3, the ditch, trench or trough in which the concrete pipe is to be cast is indicated by the numeral l and the numeral 2 indicates any preferred type of digger for progressively extending the ditch or trench as the mechanism moves forwardly, and includes mechanism nr returning the dirt to the trench Z over the cast pipe. The numeral 3 designates a pipe or chute extending downwardly and rearwardly from the machine and adapted to convey concrete mixture to the bottom of the trench or trough to form the bottom wall of the pipe to be cast, and receiving its supply of concrete mixture from the mixing machine mounted on the vehicle.

'The layer of concrete mixture just referred to is indicated by the numeral 4. Mounted rearwardly of the pipe or chute 3 is a similar pipe or chute 5 which is adapted to convey concrete mixture from the mixing machine to a point where it is discharged upon a casting cuff as will appear hereinafter. Also attached to the vehicle and adapted to travel along therewith is any preferred type of forms A adapted to shape the exterior walls of the concrete pipe being laid. Between these forms may be mounted any preferred type of Vibrator 6 for expediting the settling and packing of the concrete about the core and between the side forms.

The evertible core which forms one of the essential features of the present invention is indicated generally by the numeral l' and may be formed of any preferred type of flexible and waterproof material of suiiicient strength to perform the operations for which the core is intended. The core is formed preferably by turning inwardly one end of a liexible sleeve of the required length and passing it through the body of the sleeve and securing it to the opposite end thereof as indicated by the numeral 8. The annular but elongated compartment provided by this construction is partly filled with Water or other liquid to provide sufiicient weight to properly maintain the core in the desired position at the bottom of the trough or ditch in which the casting operation is to take place, and to aid in shaping the core to bring it to the proper circular cross-sectional contour or shape. Pieces of cork or other buoyant material B may be placed in the water to dampen any waves created in the everting operating. The core is iinally inflated by injecting air into the interior thereof and a valve 9 is provided for permitting the entrance or exit of the air as desired.

The inner wall or sleeve of the evertible tube, while changing its position from time to time as the core is everted, is indicated in Figure 2 by the numeral I0 and although containing an amount of flexible material corresponding to that of the outer Wall or sleeve Il, is necessarily constricted to a relatively small diameter by reason of the liquid and air pressures within the annular space between these inner and outer walls or sleeves I and II. Extending through the space circumscribed by the inner wall IIJ is a exible rope or cord I2. One end of this rope may be wound upon a reel on the machine and the other end wound upon a reel at a stand pipe.

The forward end of the evertible core is housed in a metal tube or casting cuff C, provided with an upwardly inclined tube C through which the rope I2 is guided on to its reel. The primary purpose of the casting cuff C is to protect the forward end of the evertible core by taking the shock of the concrete as it is poured between the forms.

In the operation of this form of the invention it will be understood that the mechanism shown in Figure 1 is moving toward the right in that gure and that the digger 2 is excavating a trench of the proper depth and width for the casting of the concrete pipe. As the machine advances, the mixed concrete travels down the chute 3 to form the bottom wall of the pipe as indicated by the numeral 4, and the chute discharges mixed concrete between the forms A and on to the top of the casting cuff C which incloses the forward end of the evertible tube 1, where it may be suitably tamped into position by the vibrator 6. As the casting machine moves forwardly the rope I2 which frictionally engages the inner wall I9 of the core draws this wall forwardly to evert the core, and this pull on the rope I2 may be provided by securing a portion thereof to a stake secured at a convenient point in the ground, or by any other preferred means. This forward pull of the rope will serve to peel off the rear portion of the outer wall II from the inner surface of the concrete pipe and automatically build up the forward portion of the core in a reverse manner so as to provide for the pouring of additional concrete mixture thereon as the process proceeds.

VThe form of the invention shown in Figures 4 to 6 inclusive is substantially the same as heretofore described with the exception of the means for everting the core, and these elements are therefore indicated by the same reference character. In this second form of the invention, a mechanically operated mechanism is provided for everting the core '1, and this mechanism is mounted in a rigid casing or casting cuff I3, depending from the vehicle carrying the concrete mixture, etc. The outer upper wall of this rigid casing, particularly the rear portion thereof, serves to receive the shock of the concrete mixture deposited by the rear pipe 5 and thus protects the forward end of the Vcore 'I to that extent, as in the previously described construction. The casing I3 also provides a mount for the everting mechanism about to be described, serves as a guide for the core, and aids in preventing the transmission of vibrations to the core.

The everting mechanism comprises a hollow plunger I4, provided with a pointed free end I5 and also provided with a plurality of perforations I6 adjacent the pointed end I5. The opposite end of the hollow plunger I4 is connected by means of a coupling hose I1, and a short pipe section I8 to a piston I9. This piston is reciprocally mounted in a cylinder and the piston is provided with a central opening 2I, adapted to communicate with the interior of the hollow plunger I4. The closed end of the cylinder 20 is indicated by the numeral 22, and adjacent thereto the cylinder is provided with a lateral tubular extension 23 opening into a valve chest 24. Also opening into the valve chest is a pipe 25 leading from a supply of pressure fluid and a pipe 26 leading from a source of vacuum. The valve mechanism Within the chest 24 is operated by means of an arm 21 provided with a yoke portion 28 straddling the plunger I4, and it is noted that the plunger is provided with a pair of spaced collars 29 and 30 adapted to engage the arm 21 as the plunger is reciprocated. When the valve operating arm 21 is moved to the left (Figure 4) by the limit stop or collar 29, the suction line is cut off and when the arm 21 is engaged by the collar or limit stop 30, the supply of pressure fluid is cut oil?, thereby controlling the reciprocation of the piston and of the plunger attached thereto. By reason of the opening 2I in the piston I9 it will be noted that when pressure fluid enters the left hand end of cylinder 20 through the pipe 23, the air pressure will enter the plunger I4, and in passing out through the apertures I6, will serve to force the .folds of fabric IB away from the plunger so as to permit the latter to travel longitudinally into the core as the pressure fluid moves the ypiston I3 to the right. Also when suction is applied to the cylinder ZU, by reason of movement of the valve rod 2l, through engagement therewith of the limit stop 30, suction will be aD- plied to the interior of the plunger I4 and acting through the perforation I6 will draw the cloth of the inner wall I0 of the core tightly against the free end of the plunger, so that as the suction draws the piston I9 to the left (Figure 5) the inner wall Ill will be drawn to the left and cause a partial everting of the core and building up of the left hand thereof, while peeling the right hand end away from the inner wall of the concrete pipe previously cast.

In this operation it will be noted that the everting of the core 'I is caused by two separate and distinct movements, namely, the movement of the rigid casing I3 which will draw the plunger I4 to the left as the vehicle moves to the left, and the everting movement caused by the travel of the plunger to the left by reason of the leftward movement of the piston I9 within the cylinder 20. In order to exercise a modified control over this everting advancement of the core 'l and prevent the core from overrunning the piston and valve mechanism located within the casing I3, a valve indicated by the numeral 3| is installed in the vacuum system, and this valve is controlled by a valve rod 32 mounted in brackets 33,1ixed to the upper side of the cylinder 2B. The opposite end of the rod 32 is provided with a disc or treadle portion 34 in line with the forward end of the core 'I, and the arrangement is such that when the forward end of the core engages the treadle portion 34, the valve 3i in the vacuum line will be closed or partly closed depending upon the extent of pressure applied to the treadle by the forward movement of the core. By this action, therefore, the leftward movement of the plunger with respect to the cylinder 20 is either completely stopped or slowed down, but upon further forward movement of the casing I3, the treadle 34 will be drawn away from the forward end of the core due to the fact that the core cannot be built up by movement of the casing I3 alone as fast as the casing travels. As soon as this separation of the treadle from the forward end of the core takes place, the valve 3I will be operated to provide a suction action on the left side of the piston, and the interior of the plunger I4 so as to continue the everting of the core by this movement supplementing the everting movement caused by the movement of the rigid casing I3. In other words, the everting action caused by the travel of the casing I3 is not suicient to cause the core to be built up forwardly at the speed of travel of the casing, and the everting action caused by the reciprocations of the plunger I4 supplements the everting action of the casing so as to always maintain the forward end of the core within the casing so as to be in position for molding the concrete as it is disposed by the pipe 5. The treadle 34 and valve 3| serve to control the advancement of the core to prevent it from overrunning the casing and the mechanism supported therein, as referred to above.

From the foregoing description taken in connection with these drawings, it will be obvious to those skilled in the art that I have devised an apparatus and method by which concrete pipe and similar structures of a monolithic type may be cast in a continuous manner without the use of various types of joints and pipe connections; that a core is provided for molding the interior of the pipe, which core is so constructed and designed as to be ev-ertible to permit the continuous casting of the pipe, and that the entire mechanism is combined in a unitary apparatus of conventional form including a moblie concrete mixer and digger so that the pipe may be cast in situ in a continuous manner as the trench, trough, or ditch is excavated by the digging apparatus.

In accordance with the patent statutes, I have described What I now consider to be the preferred forms of apparatus and the method for casting concrete pipe and similar structures in situ, but it is clearly apparent that the structure and methods may be varied without departing from the essence of the invention, and it is intended that all such variations be included within the scope of the appended claims.

I claim:

1. In an apparatus for the continuous casting of concrete pipe, an evertible core, a reciprocable plunger for everting the core, and means operated by the core for controlling the movements of the plunger.

2. In an apparatus for the continuous casting of concrete pipe, an evertible core, a rigid casing for the forward end of the core, a reciprocable plunger in the casing for everting the core, and means operated by the core for controlling the movements of the plunger.

3. In an apparatus for the continuous casting of concrete pipe, a double-walled, evertible core, a reciprocably-mounted hollow plunger provided with perforations adjacent its free end, the perforated end of the plunger being disposed within the space defined by the inner wall of the core, a pressure and vacuum system for reciprocating the plunger, said system communicating with the interior of the hollow plunger.

4. In an apparatus for the continuous casting of concrete pipe, an evertible, double-walled core of flexible material, a reciprocably-mounted hollow plunger provided with perforations adjacent its free end, the perforated end of the plunger being disposed within the space dened by the inner wall of the core, a pressure and vacuum system for reciprocating the plunger, said system communicating with the interior of the hollow plunger, and means operated by the core for controlling the movements of the plunger.

5. In an apparatus for the continuous casting of concrete pipe, an evertible core of flexible material, a pressure and vacuum system for everting the core, and means operated by the core modifying the action of said system.

6. In an apparatus for the continuous casting of concrete pipe, an evertible core of spaced interconnected cylindrical walls of flexible material, a reciprocably mounted hollow plunger and cooperating with the core and provided with perforations adjacent its free end, a cylinder and piston connected to the opposite end of the plunger, said piston provided with an opening permitting communication between the cylinder and plunger, and a vacuum and pressure system for operating the piston.

7. In an apparatus for the continuous casting of concrete pipe, an evertible core of spaced interconnected cylindrical Walls of ilexible material, a reciprocably mounted hollow plunger cooperating with the core and provided with perforations adjacent its free end, a cylinder and piston connected to the opposite end of the plunger, said piston provided with an opening permitting communication between the cylinder and plunger, a vacuum line leading to the cylinder, a valve in the vacuum line, and means associated with the core for operating said valve.

THEODORE O. ZSCHOKKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 857,587 Boyle June 25, 1907 1,348,332 Stremel Aug. 3, 1920 1,737,110 Desautels Nov. 26, 1929 2,009,362 Mourraille July 23, 1935 2,513,527 Sjodin July 4, 1950 FOREIGN PATENTS Number Country Date 355,517 Great Britain Aug. 27, 1931 

